SU994906A1 - Displacement measuring device - Google Patents

Description

(54) DEVICE FOR MEASURING DISPLACEMENTS The invention relates to a control measurement technique and can be used to measure displacements, for example, to measure the level of liquids in the chemical or petroleum industry. Inductive displacement sensors with distributed parameters are known, containing one or several inductors distributed along the moving range of the moving element, which can be performed, for example, in the form of a ferromagnetic core. CO The disadvantage of these sensors is the nonlinearity of the output characteristic at the edges of the moving range of the moving element, due to edge effects. The closest technical solution to the invention is a device for measuring displacements containing a movable element intended to interact with a controlled object in the measurement process, distributed along the displacement range of this element measuring section including the measuring winding with current leads located one from the other at a distance equal to the length of the movable element, and the resistors connected to the down-conductors by one of the clamps, and the recording device included in the dia Nal measuring bridge circuit which is formed of said measuring section (winding with resistor) and voltage divider having tappings from midpoints. The resistances of resistors connected by their terminals between adjacent current leads of the measuring winding increase as they move away from the midpoint of the winding in a ratio determined by a given shape of the output characteristic of the device. The less resistance has a resistor connected to the appropriate measuring site

3 .99 9064

winding, the lower the insertion impedance, no device can be supplied

caused by the location of the movable-winding 5 excitation, the element near this section is measured. The device for measuring the displacement section, and therefore, works as follows, the smaller the change in output voltage j When passing an alternating current

device C 2. through the measuring section around the ob-.

The disadvantage of this device is a winding 2, a magnetic field arises, and its limited linearity leads to its self-induced emf in it. On

characteristics, due to the portion of the winding 2, where

the different effects of the resistors, the ferromagnet core 1, included in the measuring section, sweeping the measured displacement X, this

the beginning and at the end of the range of measured EMF has a maximum value. For each position of the core, the purpose of the invention is to increase a certain current distribution.

the linearity of the output characteristic is ts through the resistors connected between

ki devices. by parallel through non-containing

This goal is achieved by the fact that the core parts of the coil. When you have a device for measuring the displacement of the core near the extreme lower opposite terminals of the section resistors, i.e., at the beginning, the meter is connected to a common node, their nominal JQ winding 2 is in the zero position, the resistance is the same and the current distribution is between significantly higher than the lower resistor and all the motions of the measuring section of the other resistors 3, parallel to the coil between two adjacent current-carrying wires connected through the windings, soda j and registering a device with a resistance which can be neglected, whose resistance is connected to the terminals of the resistor, the current of the measuring winding to the end of the measuring winding is connected as a result, the extreme upper resistor is cut, and then the device can also be positive, and the voltage on the second measuring section are minimal. As it moves, made similarly to the first and core 1 up along the meter connected to it by the counter-series section, the number of resistors and the distributed winding parallel to the upper one decreases, and the resistors buried parallel to the lower one,

increases. Due to this mono FIG. 1 shows a current-to-principle increase in the current through the upper resistive circuit of the device for measuring the torus and, accordingly, the current decreases.

movements; in fig. 2 - the same, differential through the lower resistor, reaching the macro-effective version of the minimum in the upper resistor when there is a device for measuring the displacement of the core 1 near the end of the measurements, contains a movable element - the ferrite winding 2 on the upper edge

romagnetic core 1 and distributed-range displacement of the core, along its range of displacements. At the same time, the voltage drop across the measuring section, including from-and-b, measured by the recording

measuring winding 2 with a collector current k - a voltmeter, also a poppy, and resistors 3. connected one at the most. from the clips to the corresponding current lead of the winding 2, and the other clips In the differential version, connected to the common node. Current Discharge Device Second Measuring

from winding 2 is made on the distance of the search, made identical to the first,

one from the other, equal to the length of the slider, is connected to it by an opposite and wide-open core 1, and the nominal ones are symmetrical to it along the range

the resistance of the resistors 3 are selected by one-displacement of the core 1, the zero one of which is much higher than the average of

the resistance of the measuring position between both measuring windings 2 between its two adjacent sections. Excitation winding 5

with leads. The recording device / 4 55 is distributed in this case along the gap to the terminals of the resistor o-b, the movement of the core 1 along

Claims (2)

connected to the end of the winding of the 2. both measuring windings 2. Output In the differential variant, the executive signal of the device is in this case the differential voltage of two voltage drops on the extreme resistors 3 of the two measuring sections, as a result of which the sensitivity of the device doubles. The proposed device provides for weakening of edge effects and obtaining a high linearity of the output characteristic, which also causes a wide range of measurable displacements (in a test sample up to 2 m). Claim 1. Device for measuring movements, containing a movable element designed to interact with a controlled object in the measurement process, distributed along the movement range of this element measuring section, including the measuring winding with current leads spaced from the other at a distance equal to element, and resistors attached to the down-conductors by one of the terminals, and registee 6. The charging device, characterized in that, in order to increase the linearity of the output characteristic, the opposite terminals of the resistors are connected to a common node, their nominal resistances are the same and much higher than the impedance of the measuring winding section between two adjacent down-conductors, and the recording device is connected to the resistor terminals, connected to the end of the measuring winding. 2. The device according to claim 1, which is equipped with a second measuring section, made similarly to the first and connected to it counter-sequentially, and distributed excitation winding. Sources of information taken into account in the examination 1. Zaripov M.F. Converters with distributed parameters. M., Energy, t969, p. 63. 2. USSR Author's Certificate No. 88074, cl. G 01 F 23/10, 1976 (prototype). ABOUT S but 413n sp3 3 P{ Fi.g uz.f